Individuals, who cannot avoid sitting in long periods of uninterrupted pressure over bony prominences and the consequent heat/moisture accumulation at such areas, including elderly individuals, persons who are neurologically impaired, and patients who are acutely hospitalized, are at increased risk for the development of pressure sore. These individuals cannot protect themselves from the pressure exerted on their body unless they consciously change position or have assistance in doing so. It is known that human body tissues are capable of withstanding enormous pressures and heat/moisture accumulation when brief in duration, but prolonged exposure to pressures may contribute to the progress of pressure sores. Thus, individuals who either consciously or unconsciously are incapable of altering their position to relieve pressure, including those having to maintain a setting position for a long period due to the nature of work, such as taxi/bus drivers, pilots, or even students and research personnel, are also at risk for the progress of pressure sore.
There are many studies about pressure relieving techniques for protecting those individuals from the risk of progressing pressure sores, one of which is disclosed in U.S. Pat. No. 7,549,707, which provides an automotive vehicle seating comfort system for providing heating, cooling, ventilation or a combination thereof to an individual in an automotive car seat and the system typically includes an insert, a blower and a tubular structure for providing fluid communication between the insert and blower for providing ventilation and/or cooling for the individual. Another study is disclosed in U.S. Pat. No. 7,331,184, which provides a hot-cold cushion capable of enabling an air circulation to be used for regulating the temperature of the cushion into a suitable range for human bodies. However, all those prior arts can only work mechanically without any knowledge about how the status of the cushion that is being used or any prediction relating to how the status of the cushion is going to be after being used for a specific period of time. Therefore, there is no feedback control mechanism being adapted for those prior-art techniques for adjusting the cushion in real-time manner and thus enhancing the performance of the same.
Therefore, it is in need of a feedback control method and device for overcoming the aforesaid shortcomings.